SRESIST,ht1,ht2,rot,kvis,selSpin coating of a thin film of photoresist

ht1 initial height of the
deposited resist in µmht2 final desired
thickness
of the resist in µmrot speed of rotation in
rpmkvis kinematic viscosity of
photoresist in cSt (centistokes)sel number denoting the
selected result.
Use 2 for time of rotation

Notes

This interface can be used to calculate the time required to produce a thin
film of photoresist by spinning it on a substrate attached to a chuck. The
resists spreads on the wafer due to the centrifugal force created by the
rotation of the chuck. The spin time is nearly independent of the initial
resist thickness especially at high thicknesses. The kinematic viscosity of
the resist is given in centistokes (1cSt = 10-6 m2/s).
Based on the desired thickness, viscosity of the resist and speed of rotation, the time of
rotation can be set.

The plot gives the time of rotation required to produce a resist of a
particular thickness. Thinner the resist, greater is the time required.

Assumptions

-The surface of the wafer is uniform. Uneven surface could affect uniform
spreading of resist.-Temperature and spin speed remains constant.